Exercise- Induced Food Allergy

There is at least one situation where more than the simple ingestion of a food to which a person is sensitive is required to provoke a reaction, and that is in exercise-induced food allergy. People who experience this reaction eat a specific food before exercising. As they exercise and their body temperature goes up, they begin to itch, get light-headed, and soon have a full-blown allergic reaction such as hives. The cure for exercised-induced food allergy is simple--not eating for a couple of hours before exercising.

Treatment

Food allergy is treated by dietary avoidance. Once a patient and the patient's doctor have identified the food to which the patient is sensitive, the food must be removed from the patient's diet. To do this, patients must read lengthy, detailed ingredient lists on each food they are considering eating. Many allergy-producing foods such as peanuts, eggs, and milk, appear in foods one normally wouldn't associate them with. Peanuts, for example, are often used as a protein source and eggs are used in some salad dressings. The FDA requires ingredients in a food to appear on its label. People can avoid most of the things to which they are sensitive, consequently, if they read food labels carefully and avoid restaurant-prepared foods that might have ingredients to which they are allergic.

In highly allergic people even minuscule amounts of a food allergen (1/44,000 of a peanut kernel for example) can prompt an allergic reaction. Other less sensitive people may be able to tolerate small amounts of a food to which they're allergic.

Patients with severe food allergies must be prepared to treat an inadvertent exposure. Even people who are very knowledgeable about what they are sensitive to occasionally make a mistake. In order to protect themselves, people who have had anaphylactic reactions to a food should wear medical alert bracelets or necklaces stating that they have a food allergy and that they are subject to severe reactions. Such people also should always carry a syringe of adrenaline (epinephrine), obtained by prescription from their doctors, and be prepared to self-administer it if they think they are getting a food allergic reaction. They should then immediately seek medical help by either calling the rescue squad or by having themselves transported to an emergency room. Anaphylactic allergic reactions can be fatal even when they start off with mild symptoms such as a tingling in the mouth and throat or gastrointestinal discomfort.

There are several medications that can be taken to relieve food allergy symptoms that aren't part of an anaphylactic reaction. These include antihistamines to relieve gastrointestinal symptoms, hives, or sneezing and a runny nose. Bronchodilators can relieve asthma symptoms. These medications are taken after people have inadvertently ingested a food to which they are allergic but are not effective in preventing an allergic reaction when taken prior to eating the food. No medication in any form can be taken before eating a certain food that will reliably prevent an allergic reaction to that food.

There are a few unproven treatments for food allergies. One involves injections containing small quantities of the food extracts, to which the patient is allergic. These shots are given on a regular basis for a long period of time with the aim of "desensitizing" the patient to the food allergen. Allergy shots have not yet been proven to relieve food allergies.

Infants and Children

Milk and soy allergies are particularly common in infants and children. These allergies sometimes do not involve hives and asthma, but rather lead to colic, and perhaps blood in the stool or poor growth. Infants and children are thought to be particularly susceptible to this allergic syndrome because of the immaturity of their immune and digestive systems. Milk or soy allergies in infants can develop within days to months of birth. Sometimes there is a family history of allergies or feeding problems. The clinical picture is one of a very unhappy colicky child who may not sleep well at night. The diagnosis is based in part on changing the child's diet. Rarely, food challenge is used.

If the baby is on cow's milk, the doctor may suggest a change to soy formula or exclusive breast milk, if possible. If soy formula causes an allergic reaction, parents should try feeding the baby with elemental formulas, which are processed proteins (basically sugars and amino acids). There are few if any allergens within these materials. Corticosteroids are also sometimes used to treat infants with severe food allergies. Fortunately, time usually heals this particular gastrointestinal disease. It tends to resolve within the first few years of life.

Exclusive breast feeding (excluding all other foods) of infants for the first 6 to 12 months of life is often suggested to avoid milk or soy allergies from developing within that time frame. Such breast feeding often allows parents to avoid infant-feeding problems, especially if the parents are allergic (and the infant therefore is likely to be allergic). There are some children who are sensitive to a certain food, however, that if the food is eaten by the mother, sufficient quantities enter the breast milk to cause a food reaction in the child. Mothers sometimes must themselves avoid eating those foods to which the baby is allergic.

There is no conclusive evidence that breast feeding prevents the development of allergies later in life. It does, however, delay the onset of food allergies by delaying the infant's exposure to those foods that can prompt allergies and may avoid altogether those feeding problems seen in infants. By delaying the introduction of solid foods until the infant is 6 months old or older, parents can also prolong the child's allergy-free period.

Controversial Issues

There are several disorders thought by some to be caused by food allergies, but the evidence is currently insufficient or contrary to such claims. It is controversial, for example, whether migraine headaches can be caused by food allergies. There are studies showing that people who are prone to migraines can have their headaches brought on by histamines and other substances in foods. The more difficult issue is whether food allergies actually cause migraines in such people. There is virtually no evidence that rheumatoid arthritis or osteoarthritis can be made worse by foods, despite claims to the contrary. There is also no evidence that food allergies can cause a disorder called the allergic tension fatigue syndrome, in which people are tired, nervous, and may have problems concentrating, or have headaches.

Cerebral allergy is a term that has been applied to people who have trouble concentrating and have headaches, as well as other complaints. This is sometimes attributed to mast cells degranulating in the brain, but no other place in the body. There is no evidence that such a scenario can happen, and cerebral allergy is not currently recognized by allergists.

Another controversial topic is environmental illness. In a seemingly pristine environment, some people have many non-specific complaints such as problems concentrating or depression. Sometimes this is attributed to small amounts of allergens or toxins in the environment. There is no evidence that such problems are due to food allergies.

Some people believe hyperactivity in children is caused by food allergies. But this behavioral disorder has only been suggested to be associated with food additives occasionally in children, and then only when such additives are consumed in large amounts. There is no evidence that a true food allergy can affect a child's activity except for the proviso that if a child itches and sneezes and wheezes a lot, the child may be miserable and therefore more difficult to control. Also, children who are on anti-allergy medicines that can cause drowsiness may get sleepy in school or at home.